The present invention relates generally to an apparatus and method for making snack food chips. More particularly, the invention relates in one aspect to an apparatus and method for making curved corn-based or other snack food chips which can be packaged neatly and compactly in a stacked arrangement, e.g., in a canister or other sleeve-type container which preferably conforms generally to the contour or perimeter of the snack food chips; and in another aspect the invention relates to an apparatus and method for making ridged or sinusoidally wavy snack food chips.
In general, snack food chips of various varieties possess characteristic shapes. For example, tortilla chips are one of the more popular types of snack food products and have come to be associated with having a triangular shape. Additionally, snack food chips which are used for dipping, e.g., potato chips, tortilla chips, or corn chips, preferably are curved to enhance the scooping ability of the chip as well as to add strength to the chip. Alternatively, chip strength may be enhanced by making the snack food chips ridged or sinusoidally wavy.
With respect to packaging, a stacked arrangement of snack food chips, e.g., in a cylindrical canister, has been found to be popular for a number of reasons. Such canisters purportedly offer some degree of protection against breakage of the snack food product and, due to the compact nature of the stacked arrangement of the chips, they provide greater transportability of the snack food products, both in terms of bulk transport (i.e., large cartons of the canisters being shipped, e.g., from the manufacturer to the retailer) as well as the individual consumer being able to transport a single package of chips (e.g., in a purse or in a picnic basket). Additionally, the extended shelf life of a sealed canister of snack food chips as compared to a bag (commonly pillow-shaped and frequently sealed with a generally inert gas to prevent product degradation), as well as the ability to reseal a canister with a snap-fit-type lid once the canister has been opened, makes a canister an attractive packaging option.
In the past, however, it has not been feasible to package a uniform stack of snack food chips such as tortilla chips in such canisters. This is because the conventional method of making snacks like tortilla chips has been simply to fry a large quantity of tortilla chips unconstrained in a fryer of cooking oil, with paddles or other means used to submerge the chips for thorough cooking and to move the chips through the oil. The chips are removed continuously from the oil in a random and non-uniform configuration. In an unconstrained environment, the chips can take on uncontrolled variations in shape, such as by folding over on themselves or partially bending. In addition, the lack of control over individual chips as they exit the fryer made it essentially impossible to package snack food chips such as tortilla chips, as previously and commonly made, in a stacked configuration such as in a canister or other sleeve-type container.
Additionally, in the past it has been difficult to impart xe2x80x9clarge-scalexe2x80x9d or xe2x80x9cmacroscopicxe2x80x9d texture to tortilla chips, e.g., by making them wavy. (In this context, xe2x80x9clarge-scalexe2x80x9d or xe2x80x9cmacroscopicxe2x80x9d texture refers to the texture or shape of the chip overall and is in contrast to xe2x80x9csurface-levelxe2x80x9d texture which may be provided, e.g., by blistering of the surface of the chips.) This difficulty was due primarily to the tacky nature of the corn dough or masa from which tortilla chips traditionally are made.
The present invention provides apparatus and methodologies for making snack food chips such as corn chipsxe2x80x94tortilla chips in particular and curved tortilla chips even more particularlyxe2x80x94which can be packaged in a stacked configuration in a canister or other sleeve-type container which preferably conforms generally to the contour or perimeter of the snack food chips. In particular, the invention features a fryer apparatus which cooks the tortilla chips by transporting them through a fryer of cooking oil while constrained within continuous, preferably two-piece semi-closed molds. Preferably, the apparatus includes a pair of belts which mate to define the molds, one belt consisting of links which define concave, lower mold cavities and the other belt consisting of links which form convex retaining protuberances which restrain the tortilla chips in the mold cavities. A die-cutting vacuum transfer wheel is used to cut tortilla chip preforms (uncooked tortilla chips) from a continuous, toasted, proofed sheet of corn masa and place the preforms into the mold cavities in the lower belt assembly. A vacuum transfer wheel is also provided downstream, at the exit end of the fryer apparatus, to transfer the now-cooked tortilla chips from the mold cavities to a take-away conveyor which transports the tortilla chips to be seasoned, if desired, and ultimately to a packaging stationxe2x80x94doing so in a manner which maintains the regular orientation of the chips that is necessary to be able to stack them for packaging.
In other aspects, the invention features methodologies which enable form-frying of tortilla chips in semi-closed, constrained molds in regular order so as to produce uniformly shaped chips that can be stacked for packaging. Thus, in one methodological aspect, the invention features placing tortilla chip preforms into a first mold section; constraining the tortilla chip preforms in the first mold section by enclosing them in the mold using a mating second mold section and immersing the tortilla chip preforms in hot oil to cook them. The tortilla chip preforms are loaded into the molds in a regular or uniform arrangement, and they are removed from the molds and processed subsequent to their being fried while maintaining the regular or uniform arrangement. This permits them to be stacked for packaging. Preferably, the tortilla chips are transported through the hot oil, e.g., by means of a belt configuration. This permits the tortilla chips to be cooked on a continuous basis instead of on a batch basis (which also is deemed to be within the scope of the invention).
In another methodological aspect, the invention features a departure from conventional pre-processing of tortilla chips, in which conventional pre-processing corn masa is first cut into the raw tortilla chip preforms which are then toasted and proofed to bring the moisture content of the preforms to a required level before they are cooked in oil. According to this aspect of the invention, the corn masa is sheeted then toasted and proofed before being cut into the individual tortilla chip preforms and cooked, e.g., in enclosed molds. This order of the process steps is used in particular when the tortilla chips are to be packaged in a uniform, stacked arrangement because it was found that uniform orientation of the tortilla chip preformsxe2x80x94which is necessary in order to be able to transfer the tortilla chip preforms repeatedly and reliably into the molds and then subsequently to be able to stack and package the cooked chipsxe2x80x94could not be maintained if the tortilla chip preforms were cut from the relatively sticky or tacky corn masa sheet before being toasted and proofed. Thus, to a relatively large extent, toasting and proofing the corn masa sheet before die-cutting the tortilla chip preforms is the step which enables stackable tortilla chips to be manufactured efficiently and on a commercially viable scale.
Additionally, toasting and proofing the sheet of masa makes it feasible to provide, on a commercially viable scale, xe2x80x9cmacroscopicxe2x80x9d texture to the tortilla chips, e.g., by passing the sheet of masa through one or more corrugated rollers, check rollers, embossing rollers, waffle cut rollers, or other forming step after it has been toasted and proofed and before it is die-cut to produce the chip preforms. Again, it is the reduction in stickiness or tackiness occasioned by toasting and proofing that renders this processing step commercially feasible. When so shaping the chip preforms, it may be desirable to forego the subsequent molding of the chip preforms (by, for example, frying them in mold cavities as described above); in that case, the chip preforms could be baked or fried unrestrained, in a manner as is known in the art.